module Test::Unit::Attribute::ClassMethods

def attribute(name, value, options={}, *method_names)
  unless options.is_a?(Hash)
    method_names << options
    options = {}
  end
  if method_names.empty?
    current_attributes[name] = options.merge(:value => value)
  else
    method_names.each do |method_name|
      set_attributes(method_name, {name => value})
    end
  end
end

def attribute_observers(attribute_name)
  @@attribute_observers[attribute_name]
end

def attributes(method_name)
  attributes = attributes_table[method_name]
  ancestors.each do |ancestor|
    next if ancestor == self
    if ancestor.is_a?(Class) and ancestor < Test::Unit::Attribute
      parent_attributes = ancestor.attributes(method_name)
      if attributes
        attributes = (parent_attributes || {}).merge(attributes)
      else
        attributes = parent_attributes
      end
      break
    end
  end
  attributes || StringifyKeyHash.new
end

def attributes_table
  @attributes_table ||= StringifyKeyHash.new
  super.merge(@attributes_table)
end

def current_attribute(name)
  current_attributes[name] || StringifyKeyHash.new
end

def current_attributes
  @current_attributes ||= StringifyKeyHash.new
end

def find_attribute(method_name, name, options={})
  recursive_p = options[:recursive]
  recursive_p = true if recursive_p.nil?
  @attributes_table ||= StringifyKeyHash.new
  if @attributes_table.key?(method_name)
    attributes = @attributes_table[method_name]
    if attributes.key?(name)
      return attributes[name]
    end
  end
  return nil unless recursive_p
  return nil if self == TestCase
  @cached_parent_test_case ||= ancestors.find do |ancestor|
    ancestor != self and
      ancestor.is_a?(Class) and
      ancestor < Test::Unit::Attribute
  end
  return nil if @cached_parent_test_case.nil?
  @cached_parent_test_case.find_attribute(method_name, name, options)
end

def method_added(name)
  super
  return unless defined?(@current_attributes)
  attributes = {}
  kept_attributes = StringifyKeyHash.new
  @current_attributes.each do |attribute_name, attribute|
    attributes[attribute_name] = attribute[:value]
    if attribute[:keep]
      keep_hook = attribute[:keep_hook]
      attribute = keep_hook.call(attribute) if keep_hook
      kept_attributes[attribute_name] = attribute
    end
  end
  set_attributes(name, attributes)
  @current_attributes = kept_attributes
end

def register_attribute_observer(attribute_name, observer=nil, &block)
  observer ||= Proc.new(&block)
  @@attribute_observers[attribute_name] ||= []
  @@attribute_observers[attribute_name] << observer
end

def set_attributes(method_name, new_attributes)
  return if new_attributes.empty?
  @attributes_table ||= StringifyKeyHash.new
  @attributes_table[method_name] ||= StringifyKeyHash.new
  current_attributes = @attributes_table[method_name]
  new_attributes.each do |key, value|
    observers = attribute_observers(key) || []
    observers.each do |observer|
      observer.call(self,
                    StringifyKeyHash.stringify(key),
                    (attributes(method_name) || {})[key],
                    value,
                    method_name)
    end
    current_attributes[key] = value
  end
end